1. Field of the Invention
This invention relates to a braided polyester suture made from high-tenacity polyester yarn filaments.
2. Related Background Art
Braided sutures are well known in the art as disclosed, for example in U.S. Pat. No. 5,019,093. Various natural and artificial polymeric materials have been used in manufacture of braided sutures, including surgical gut, silk, cotton, polyolefins, polyamides, polyglycolic acid and polyesters. Braided polyester sutures are useful in applications where a strong, nonabsorbable suture is needed to permanently repair tissue. They are frequently used in cardiovascular surgery, as well as in ophthalmic and neurological procedures. Examples of commercial braided polyester sutures are ETHIBOND EXCEL.RTM., manufactured by Ethicon, Inc., TICRON.RTM. manufactured by Sherwood-Davis & Geck and TEVDEK.RTM. manufactured by Deknatel.
The surface roughness of braided sutures is of great importance to surgeons. Excessive roughness affects the knot-tying and knot-holding properties of the suture, causing an uneven movement known as "chattering." This characteristic increases the difficulty of accurately placing knots. In addition, the uneven force exerted on the suture during tying may lead to increased suture breakage. Typically, sutures are coated with a lubricating material, e.g., polybutilate, to improve the handling characteristics of the sutures.
In addition, conventional polyethylene terephthalate (PET) sutures can exhibit reduced tensile strength and have a tendency to fray. This also leads to increased suture breakage during tying of surgeon's knots.
U.S. Pat. No. 5,318,575 discloses use of high-tenacity, low-elongation fibers to produce a reinforced band for attaching tissue or bone. However, the high-tenacity, low-elongation fibers are made from polyethylene of extremely high molecular weight, with other materials being used only as filler yarns. No suggestion is made that high-tenacity polyester fibers would be suitable for use in surgical repair products.